China and Russia: Best frenemies forever?

FORTUNE — Chinese leader Xi Jinping’s choice of first overseas stop shortly after his inauguration as the new Communist Party chief and the president of the country has raised some eyebrows. Instead of visiting a major Western capital, he picked Moscow as his diplomatic launching pad.

In light of Xi’s eagerness to present himself as a reformer in the mode of the late Deng Xiaoping, Moscow is an even more curious choice, since Deng’s first foreign destination after gaining political dominance in December 1978 was Washington. It was clear that Deng knew his reform could not succeed without the help of the West, in particular the United States. But what is Xi thinking this time?

Apparently, Xi wants to send a message to the West: China has other important friends in the world and does not need the West as much as it used to.

On the surface, warmer ties between China and Russia, two former bitter foes during the Cold War, make strategic and commercial sense. Ideologically, the authoritarian ruling elites in both countries resent the West’s push for democracy and view such efforts as a political threat. They particularly abhor the West’s penchant for regime change and infringement on other countries’ sovereignty (that is why Beijing and Moscow jointly vetoed a United Nations Security Council resolution on Syria a year ago).

Economically, there also appears to be a good fit between Russia’s enormous wealth of natural resources and China’s insatiable appetite for them. Bilateral trade between the two nations has more than doubled in the last five years, reaching $88 billion in 2012. Unsurprisingly, the most trumpeted business deal struck during Xi’s stop in Moscow was a memorandum of understanding for Gazprom, Russia’s giant state-owned natural gas company, to supply China with 38 billion cubic meters of natural gas per year after 2018 (although the two sides remain far apart on the price, which has to be negotiated). Chinese and Russian energy companies also announced smaller agreements, one of which involves a $2 billion joint venture in coal mining in Russia’s Far East.

Militarily, Russia has been China’s most important foreign supplier of advanced weapon systems. In the 1990s, a period of friendly relations between the two countries, Russia sold China sophisticated jetfighters, destroyers, and diesel submarines, enabling the People’s Liberation Army to acquire critical capabilities quickly. After Vladimir Putin came to power in 2000, military sales to China quickly came to a halt. Putin was worried about giving China the weapon systems that could one day threaten Russia itself while China was unhappy about the restrictions Russia placed on the military hardware it was exporting to China. But during the summit between Xi and Putin this month, China managed to get hold of more advanced weapon systems: 24 Su-35 fighters (fourth-generation systems with stealth capability) and four Lada-class diesel submarines (an upgrade from the Kilo-class, which China has already purchased). In the context of Washington’s “pivot” to Asia, Beijing’s purchase of these platforms clearly sends a message.

This long list of overlapping interests may lead one to think that a strategic partnership between China and Russia is natural, if not inevitable. Indeed, this is exactly how Xi and Putin characterize Sino-Russo ties.

However, such descriptions are deceiving. In spite of the superficial warmth exhibited at the Moscow summit, China and Russia are deeply wary of each other. If anything, their ties have rested on shaky foundations since the fall of the Soviet Union.

Sino-Russo relations are rife with historical distrust and latent geopolitical rivalry. China may be rising, and Russia may be declining, but Russia continues to see itself as a superpower with a say in Asia and a stake in protecting its zone of influence, particularly in Central Asia. At the same time, China views its role as Asia’s dominant power and relegates Russia to a secondary role in Asia. Indeed, the United States and Japan figure far more prominently in China’s strategic calculus regarding Pacific-Asia.

That is why Russia often has to reassert itself to demonstrate its clout and relevance. In regional security, Russia has been a staunch supporter of Vietnam, a troublesome neighbor for China. Moscow has sold Hanoi six advanced Kilo-class submarines and 12 Su-30MK fighter jets, which could threaten China’s vital shipping lanes in the South China Sea. In Central Asia, Russian resistance has hampered China’s ability to expand its profile (at least on one occasion, Russia scuttled a huge energy deal sought by China in the region).

Even Russia and China’s ostensibly mutually beneficial energy trade has been full of ups and downs. Many deals have been announced, but only a few have come to fruition. As a supplier, Russia wants to get as high a price as possible and as many buyers as it can. As a customer, China is eager to drive down prices and make itself Russia’s sole purchaser in Asia. It took 10 years of painful negotiations before Russia began to ship oil to China via a pipeline that Moscow initially refused to build (mainly because Russia wanted to extend the pipeline to the Pacific so it could supply Japan and Korea). For the privilege of getting Russian oil, China had to make a $20 billion loan in return for guaranteed supply for 20 years. The mammoth gas deal initialed in Moscow during Xi’s visit may not materialize because neither side has agreed on a price.

Yet, in spite of their mutual wariness, China and Russia find, for the moment at least, some utility in showcasing their friendship. The real audience of the Xi-Putin Summit in Moscow was Washington. Both China and Russia believe that their marriage of convenience will somehow strengthen their bargaining positions with the United States.

Minxin Pei is the Tom and Margot Pritzker ’72 Professor of Government at Claremont McKenna College and a non-resident senior fellow at the German Marshall Fund of the United States.